Electric vs mechanical fan

[Madhorn]

It's not a big enough gain to feel. Did you fix something else?

There was a little gain, but not much with electric fans. The cold air intake gave a greater feel of extra power. Without before and after dyno numbers it is impossible to state a HP gain. Seat of the pants HP calculations are never close to reality. But when the truck runs better, it’s a win.

 

[SquareRoot]

My 85 k20 with 350/th400:

I run a two core all aluminum radiator, spal dual 11 inch fans with integrated shroud, Dakota Digital controller and a powermaster 150 amp alternator.

It's an awesome setup and works great here in Southern Arizona where summer temps are 105-120.

Recently, on the way home from a desert run, the fans suddenly quit and I had to pull into a parking lot to investigate. I had a loose connection in an auxiliary power block that fed the controller.

Easy fix but I'm a die-hard for simple reliability and quick fixes to get me home.

Sooo....I wanted the ability to override the controller in an emergency. I added two micro switches and LED's in the bezel where the shift indicator used to be. That area gets blocked off with Dakota Digital guages (see pic). Anyway, out of sight and stealthy yet readable and easy to monitor. So one switch is just a ground input to the low fan relay and the other to the high side relay. The led gets 12volt at the fan input wire at the fan. With two fans, separate relays and override switches, it's kind of redundancy overkill.

I can't speak highly enough of Dakota Digital. There vhx and fan controller are excellent!

My .02 cents about added hp and milage...moot point. Your still pushing a 5000 # brick around. You won't notice any difference either way. And, IMO/ experience, a good working mechanical fan is just as effective in these vehicles.

Why then do we still spend big bucks and go thru the hassle of modifying our vehicles? Cause we're hottrodders with ideas and it drives us to be different whether it's a good idea or not. If we didn't experiment we'd still be living in caves and dragging the ol' lady around by her hair.

Now I just need to finish that nv4500 swap and lose the slushbox.

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[Brett77]

502 Stoker here in Arizona, stock fan and shroud never runs hot.

 

[Brett77]

502 Stoker here in Arizona, stock fan and shroud never runs hot.

 

[JTWard]

if it’s staying at 160 now then i would leave it alone, i wouldn’t be afraid of it running up around 210 either. running too cold can hurt the power the motor makes. on my chevelle, it made about 15hp more of it was running 210 degrees instead of at 160 degrees.

I've seen this pitch many times before and I'll give you a valuable little tip of Advice. . . Don't add anything or if you must, just get an oversized aluminum cored radiator. Since we're only dealing with gas engines, any, any ,any motor oil comes with an additives package ( That's what the Oil Companies call it) with detergent, friction modifiers and other chemicals so on. But many of the fluides in the coolant additives package don't ever start to work till the fluid is over 200 degrees. I have 2015 tahoe and that 5.3 liter engine runs all day in the 210 degrees and on a very hot day in rush hour traffic it'll get up to 220 degrees. if I'm out on the expressway at high speed again it'll get up to 220. But don't be scared until it's gets toward 250 degrees. Two hundred degrees with a 16 psi cap ? hell your wife cooks the Thanksgiving turkey at 350 degrees. My 88 Blazer has it's 30 year old aluminum radiator and still on a hot humid day will wander around 210 degrees. A little bit of heat isn't a bad thing !

 

[SquareRoot]

I've seen this pitch many times before and I'll give you a valuable little tip of Advice. . . Don't add anything or if you must, just get an oversized aluminum cored radiator. Since we're only dealing with gas engines, any, any ,any motor oil comes with an additives package ( That's what the Oil Companies call it) with detergent, friction modifiers and other chemicals so on. But many of the fluides in the coolant additives package don't ever start to work till the fluid is over 200 degrees. I have 2015 tahoe and that 5.3 liter engine runs all day in the 210 degrees and on a very hot day in rush hour traffic it'll get up to 220 degrees. if I'm out on the expressway at high speed again it'll get up to 220. But don't be scared until it's gets toward 250 degrees. Two hundred degrees with a 16 psi cap ? hell your wife cooks the Thanksgiving turkey at 350 degrees. My 88 Blazer has it's 30 year old aluminum radiator and still on a hot humid day will wander around 210 degrees. A little bit of heat isn't a bad thing !

hell your wife cooks the Thanksgiving turkey at 350 degrees

Lol, you haven't seen my wife cook! I had to explain to her the fire alarm was NOT the oven timer.

 

[shiftpro]

My 85 k20 with 350/th400:

I run a two core all aluminum radiator, spal dual 11 inch fans with integrated shroud, Dakota Digital controller and a powermaster 150 amp alternator.

It's an awesome setup and works great here in Southern Arizona where summer temps are 105-120.

Recently, on the way home from a desert run, the fans suddenly quit and I had to pull into a parking lot to investigate. I had a loose connection in an auxiliary power block that fed the controller.

Easy fix but I'm a die-hard for simple reliability and quick fixes to get me home.

Sooo....I wanted the ability to override the controller in an emergency. I added two micro switches and LED's in the bezel where the shift indicator used to be. That area gets blocked off with Dakota Digital guages (see pic). Anyway, out of sight and stealthy yet readable and easy to monitor. So one switch is just a ground input to the low fan relay and the other to the high side relay. The led gets 12volt at the fan input wire at the fan. With two fans, separate relays and override switches, it's kind of redundancy overkill.

I can't speak highly enough of Dakota Digital. There vhx and fan controller are excellent!

My .02 cents about added hp and milage...moot point. Your still pushing a 5000 # brick around. You won't notice any difference either way. And, IMO/ experience, a good working mechanical fan is just as effective in these vehicles.

Why then do we still spend big bucks and go thru the hassle of modifying our vehicles? Cause we're hottrodders with ideas and it drives us to be different whether it's a good idea or not. If we didn't experiment we'd still be living in caves and dragging the ol' lady around by her hair.

Now I just need to finish that nv4500 swap and lose the slushbox.

You must be registered for see images attach

[/QUOTE

Nice report, thanks. It's always nice to hear good things about a component that you have already bought. My research led me to Dakota Digital.
I thought of the same emergency fix, but my idea was to make a small wiring harness to just unplug and bypass the controller. Maybe your idea is better...

 

[82sbshortbed]

dragging the ol' lady around by her hair.

Are we not supposed to do that anymore? She seems to listen better after a good drag around by the hair.

 

[RecklessWOT]

On every vehicle I've ever switched to electric fan there was a real, very noticeable power increase. You are physically taking a wind break off of the rotation of your engine. Idk how much numbers wise, but it's less work those rotating parts of your engine have to do to push that stupid fan around. Ever try to swing a piece of plywood through the air? You can feel the resistance pushing back. Your engine feels it too.

Wiring an electric fan is super easy and cheap to do as well so IMO it is definitely worth it. Only reason I haven't done my burb yet is because it runs fine the way it does and I have more important stuff to work on first, wayyy too busy to go play with the square. It's definitely on the list of things to do though.

And I wouldn't worry about the fact that you have a 160deg thermostat but the fans will only come on between 170-185, it won't make the truck run hotter. I've run trucks without fans before and it was fine as long as you can keep moving. The wind coming through your grille at 35mph is far more than any fan will pull for you. They will only turn on when sitting at a red light or stuck in bumper to bumper traffic. At that point they only exist to prevent you from overheating, and even at 180deg you're nowhere near overheating. When you're actually driving around there will be no change in temperature and no loss in power if that's what you're worried about.

 

[DoubleDingo]

Hello everyone, here is the situation. My current set up in my 1983 c10. 3 core rad, with full shroud, 7 blade metal fan driven by water pump fan clutch, also running a 160 thermostat. Truck is only driven during summer months, temp according to the gauge always hovers around the 160 mark.

So onto my dilemma, I got a really really really good deal on some flex a lite electric fans, so I was thinking of installing a dual puller fan set up that's draws 2500cfm inside the shroud where it would cover almost the entire rad except maybe 2 inches on top and bottom. I want to run this set up with a relay and a thermostat switch.

I may be over thinking this but I feel as though it may be counter productive. Reasoning is that by installing the thermostat switch that kicks fans on at 185 and off at 175 the coolant never gets back down around the thermostat temperature. Therefore running hotter and decreasing the power that would be gained from not running the mechanical fan.
Please help.

If you have a fully functioning stock fan clutch setup and fully functioning radiator that keeps things cool, then just get a 180* or 195* thermostat and call it good. I have a fully functioning system with a 180* thermostat and the needle never goes above the first line on the gauge, ever.

 

[DoubleDingo]

Thank you all for the input. I think I'm just going to leave it alone. I guess if it's not broke don't fix it. I'm also running my temp sensor in the water outlet right above the thermostat is that ok or should I be running it in the intake or the head?

Mine came installed on the driver's side head, and it still stays at the first mark on the gauge. To me you get a more accurate temp reading from the head as that's where all the heat-action is.

 

[Matt69olds]

In my opinion, unless your running a mechanical fan with no clutch, you won’t feel a performance difference by switching to electric. A mechanical fan with a thermal fan clutch free wheels until the engine temp is high enough to engage the clutch. It has been proven with engine and chassis dyno tests, and I have tried it on the track. A time slip is much more accurate than a seat of the pants feeling. I’m guessing the perceived increase in performance felt by your “butt-o-meter” is more due to the reduction in noise.

 

[SquareRoot]

Exactly Matt. Well put.